1. Field of the Invention
This invention relates to a filter unit for brewing filtered coffee with a filter basket which is designed to receive basket filter bags and having a basket bottom supplied with filter openings.
2. Description of Prior Art
Filter units with basket filter bags are used today primarily in the restaurant business. Such filter units are particularly suited for brewing large amounts of filtered coffee at one time, something which is not possible with the cone-shaped filter units used today in private homes.
A filtering device for brewing filtered coffee which has a filter basket for receiving basket filter bags is known from Applicant's Swiss Patent CH 486 233. The filter basket has a bottom which is provided with ring-shaped grooves. Filter openings are positioned at regular distances in the ring-shaped grooves. Depressions are located between drip holes on the underside of the bottom. A bottom with such grooves and depressions aids the formation of drops at the filter openings.
Other known filtering devices have a great disadvantage in that the flow of the processed coffee out of the filter unit into a container does not occur continuously. In these devices, as the water level in the filter basket falls below a certain level, the outflow of water begins to slow or even stops. This problem was partially solved with the above mentioned patent.
A further problem arises during the pouring of hot water into the filter unit with the basket filter bag. Because these filter units are shaped like a cylinder or truncated cone, the water is distributed as a function of the pouring location and the pouring speed. In the process, powdered coffee is forced along and generally deposited unevenly on the walls of the basket filter bag. Often, a depression forms in the powdered coffee above the bottom of the basket filter bag because of the coffee that has floated away. These problems also have an effect on the flow of coffee out of the filter unit, and generally lower the quality of the filtered coffee. The uneven distribution of the powdered coffee plays a considerably greater role in connection with filter units of smaller size for the private household. For this reason, such filter units have not gained wide acceptance in private households.